Fire and Police services in four Southern Idaho counties - Lincoln, Gooding, Jerome and Twin Falls - needed to improve communications and reduce costs by consolidating to a single despatch system. Radio users are spread across a wide area.
The users of the emergency services’ mobile radios are spread across a large area, but required a system that gave them all access to the same radio channel. They identified that a simulcast system - that simultaneously broadcasts from many transmitters on the same frequency - would deliver what they needed.
However, simulcast systems can be expensive to buy and maintain because precise control of the transmitters is required to receive an undistorted audio signal in coverage overlap areas. Over time the transmitter frequencies drift and the audio signals that modulate the transmitters have to be corrected.
The Fire and Police Services chose a TaitNet Quasi-Sync system for its key advantage over traditional technology: the Tait system uses advanced computer technology to virtually eliminate the maintenance. TaitNet QS uses high stability oscillators to maintain a very stable transmitter frequency.
Tait North America, in conjunction with dealer Teton Communications, installed a four-channel system with a total of 20 sites for the emergency services in Southern Idaho:
- One Police data channel (five sites)
- One Fire voice despatch channel (six sites)
- One Police voice despatch channel - northern area (five sites)
- One Police voice despatch channel - southern area (four sites)
- The network uses 45 Tait base stations/repeaters across the four counties
The new system delivers high audio quality to areas not previously covered. Digital signal processing-based Line Equalizer Modules that route audio to each transmitter, analyze the characteristics of the neighboring transmitter and automatically adapt their own signal to match.
Other case studies
This positioning paper will provide a summarized comparison of the current digital technologies outlining the advantages and disadvantages for each of them. The technologies compared are DMR, dPMR, TETRA, TETRAPOL, P25, NXDN and Opensky.